SKM 2021 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 21: Focus Session: Topological Kagome Metals

TT 21.1: Hauptvortrag

Donnerstag, 30. September 2021, 13:30–14:00, H7

A new class of charge density wave superconductors in the topological kagome metals AV₃Sb₅ (A=K, Rb, Cs) — •Stephen Wilson — Materials Department, University of California Santa Barbara

Kagome metals are compelling materials platforms for hosting electronic states that feature an interplay between topologically nontrivial electronic states and correlated electron phenomena. These two features can, for instance, arise from the Dirac points, flatbands, and saddle-points endemic to the kagome lattice type in simple tight-binding models. Recently in this field, the discovery of a new class of kagome metals of the form AV₃Sb₅ with A=K, Cs, or Rb has provided a unique setting for exploring the interplay between Z₂ electronic topology and intertwined charge density wave and superconducting orders. These metals realize a kagome lattice of nonmagnetic vanadium ions with an electron-filling that populates saddle-points and their corresponding van Hove singularities in the electronic density of states near the Fermi level. Nesting effects in this setting are predicted to stabilize a variety of unusual states, ranging from charge density wave order that breaks time reversal symmetry to unconventional superconductivity. Here I will present some of our recent work exploring the phase transitions and broken symmetries in these materials. Particular attention will be given to the nature of the charge density wave instability.